Search

A thick section plate specimen of a completely refined Gr.91 steel plate met the requirements of ASME code concerning the toughness and creep strengths due to exact control of the chemical composit...

In this study, we investigated the temperature dependence of magnetostriction in the twinned rhombohedral perovskite structure-based lanthanum cobaltite La0.8Sr0.2CoO3. The magnetostriction measured in a magnetic field applied along the pseudocubic [111]c axis showed large hysteresis and residual strains. The residual strains are caused by the twin deformation, which we observed using x-ray diffraction. We found that the critical magnetic field for the twin deformation of La0.8Sr0.2CoO3 increases with temperature. The twin deformation occurs in a sufficiently strong magnetic field (∼6 T), even in the paramagnetic region at room temperature. We also confirmed that the temperature dependence of the critical magnetic field for twin deformation is related to the temperature dependence of the magnetization.

Human embryonic stem cells (hESCs) and induced pluripotent cells have the potential to provide an unlimited source of tissues for regenerative medicine. For this purpose, development of defined/xeno-free culture systems under feeder-free conditions is essential for the expansion of hESCs. Most defined/xeno-free media for the culture of hESCs contain basic fibroblast growth factor (bFGF). Therefore, bFGF is thought to have an almost essential role for the expansion of hESCs in an undifferentiated state. Here, we report identification of small molecules, some of which were neurotransmitter antagonists (trimipramine and ethopropazine), which promote long-term hESC self-renewal without bFGF in the medium. The hESCs maintained high expression levels of pluripotency markers, had a normal karyotype after 20 passages, and could differentiate into all three germ layers.

Heteroxylans in the plant cell wall have been proposed to have a role analogous to that of xyloglucans or heteromannans, forming growth-restraining networks by interlocking cellulose microfibrils. A xylan endotransglycosylase has been identified that can transglycosylate heteroxylan polysaccharides in the presence of xylan-derived oligosaccharides. High activity was detected in ripe fruit of papaya (Carica papaya), but activity was also found in a range of other fruits, imbibed seeds and rapidly growing seedlings of cereals. Xylan endotransglycosylase from ripe papaya fruit used a range of heteroxylans, such as wheat arabinoxylan, birchwood glucuronoxylan and various heteroxylans from dicotyledonous primary cell walls purified from tomato and papaya fruit, as donor molecules. As acceptor molecules, the enzyme preferentially used xylopentaitol over xylohexaitol or shorter-length acceptors. Xylan endotransglycosylase was active over a broad pH range and could perform transglycosylation reactions up to 55 °C. Xylan endotransglycosylase activity was purified from ripe papaya fruit by ultrafiltration and cation exchange chromatography. Highest endotransglycosylase activity was identified in fractions that also contained high xylan hydrolase activity and correlated with the presence of the endoxylanase CpaEXY1. Recombinant CpaEXY1 protein transiently over-expressed in Nicotiana benthamiana leaves showed both endoxylanase and xylan endotransglycosylase activities in vitro, suggesting that CpaEXY1 is a single enzyme with dual activity in planta. Purified native CpaEXY1 showed two- to fourfold higher endoxylanase than endotransglycosylase activity, suggesting that CpaEXY1 may act primarily as a hydrolase. We propose that xylan endotransglycosylase activity (like xyloglucan and mannan endotransglycosylase activities) could be involved in remodelling or re-arrangement of heteroxylans of the cellulose-non-cellulosic cell wall framework.

A simple heat treatment was used to fabricate carbonaceous layer-coated electrodes: micro-ring electrodes and conductive stainless steel. Substrates of sharpened quartz capillaries or type-316 stainless steel plates were put in an alumina boat with powder of petroleum pitch A240F separately and heated at 1073–1273 K in a flow of nitrogen or argon. By this treatment, both of the substrates were coated with a uniform carbonaceous layer of several hundred nano-meters in thickness. The electric conductivity of the layer was improved by increases in temperature and period of the heating. The quartz glass-capillary covered with the conductive layer was modified to a needle-type microelectrode by coating with an insulating polymer and baring the tip. At least a dozen carbon micro-ring electrodes with an outer radius of about 1 μm were successfully prepared by the simple heat treatment. On the other hand, the carbonaceous layer formed on type-316 stainless steel showed relatively poor conductivity due to the formation of oxides in the layer. However, the conductivity was improved by electroplating of nickel on the substrate before the heating. The carbonaceous layer-coated stainless steel showed good corrosion resistance in sulphuric acid.

The gold deposition development method instead of the normal development method was applied to a nuclear track detector by using silver halide photography. Fine tracks formed by spherical gold grains were observed without any filaments. The grain size does not depend on the initial size of the silver halide crystals but only on the deposition period. This implies that the grain size can be adjusted to a size similar to the resolving power of an optical microscope in spite of the use of an ultra-fine crystal emulsion. In addition, the developer used in the gold deposition method does not contain harmful organic reagents, and it contains a lower amount of inorganic salts than normal developers. The solution can be safely handled and the disposing treatment of the solution is easy.

Metabolic experiments were conducted for each Thai native (TN) and Anglo Nubian–TN 50% (AN × TN) bucks, 26.5–38 kg BW and 35–52 months of age, by assigning the following concentrate diets, which had four levels of CP concentrations, T1: 14%, T2: 21%, T3: 28% and T4: 35%, on a DM basis. The animals were fed the concentrates at a rate of 1% of their BW and had ad libitum access to Paspalum plicatulum hay. As the CP level increased, digestibility of CP, N excretion in urine and N retention increased ( P P 0.75 day) versus 36.0 g/(kg BW 0.75 day)), thus N intake of AN × TN was higher than that of TN ( P 0.75 day) versus 0.90 g/(kg BW 0.75 day)). Digestibility of CP and blood urea N concentrations of TN were higher than those of AN × TN ( P 0.75 day) versus 0.11 g/(kg BW 0.75 day)) and T4 (0.25 g/(kg BW 0.75 day) versus 0.17 g/(kg BW 0.75 day)). Digestibility of NDF and ADF, and TDN of TN were higher than those of AN × TN ( P 0.75 day), and no significant difference of DE among CP levels nor breeds of bucks was observed. Thai native was superior to AN × TN in digestibility of N and fiber fractions at the maintenance level of DE, which might have overcome inferiority of TN to AN × TN in amount of N and energy intake caused by the lower DMI. It is likely that TN goats are well adapted to fodder shortage condition due to their efficient utilization of nutrients.

Aims The prognosis of renal cholesterol crystal embolism (CCE) is poor. Although various treatments for CCE have been attempted, there is no optimal therapy. We tested the effect of low-dose prednisolone (PS) on CCE-related acute renal failure (ARF). Patients and methods 7 patients (mean age 69 years) diagnosed with CCE-related ARF were treated with oral PS at 15-20 mg/day for 2-4 weeks, which was then tapered at 5 mg/day over 2-4 weeks, followed by 5 mg/day maintenance dose. Recurrent ARF during PS tapering was treated with a larger dose of PS. Results Inciting factors were identified in four patients: coronary angiography (n=3) and cerebral angiography (n=1). On admission, serum creatinine (SCr) was 2.1 +/- 0.3 mg/dl (mean +/- SEM). SCr and eosinophil count before treatment were 4.2 +/- 0.4 mg/dl and 682 +/- 73/microl, respectively. PS therapy improved ARF in all cases at week 2 (SCr 3.8 +/- 0.5 mg/dl) parallel to a decrease in eosinophilia (116 +/- 30/microl), and at week 4 (3.1 +/- 0.4 mg/dl and 134 +/- 20/microl, respectively). At last follow-up, renal function was improved or maintained in 5 patients compared with that at week 4 post-treatment. One patient died of lung cancer. Another required LDL apheresis and hemodialysis but died due to CCE-related multi-organ failure. A third patient had recurrent ARF and was re-treated with a larger dose of PS, which resulted in an immediate decrease in SCr. However, the patient developed acute renal dysfunction due to congestive heart failure, and required hemodialysis. Conclusions Low-dose PS improved CCE-related ARF, probably through amelioration of inflammatory reaction surrounding affected renal vessels.

We report the single-pass second harmonic generation (SHG) of the picosecond Ti:sapphire laser with a periodically poled lithium niobate (PPLN) waveguide. We demonstrate a conversion efficiency of 37% for the 9-mW fundamental input power at 820 nm. This laser source can provide three types of pulsed modes such as picosecond, nanosecond, and contiuous wave, by adjusting the power of the pumping source. We compare the conversion efficiency in each mode, and clearly show that SHG efficiency depends on the pulsewidth, that is, the peak power of the laser source. As the temperature of the PPLN rises, the fundamental wavelength for phase-matching becomes longer. We indicate that the rate is about 0.06 nm/K. q 2004 Elsevier Ltd. All rights reserved.

We have first developed an all-solid-state 252 nm coherent light source for laser cooling of silicon atoms. This can give an impetus to research into the manipulation of the atomic motion of silicon atoms toward nanoprocess applications. Therefore, we developed an experimental setup for silicon atom manipulation. It was found that a high-quality silicon atomic beam, useful for nanoprocess applications, is obtainable with manipulation using the coherent light source in the system. With this unique apparatus, we continue the challenge to demonstrate the spatial design of nuclear spins of the family of isotopes with laser cooling of Si.

A permanent structure of a single-mode waveguide in optical multimode fluoride fibers was first fabricated using a self-channeled plasma filament excited by a femtosecond (110-fs) Ti:sapphire laser (λp=800 nm). The photoinduced refractive-index modification in a multimode step-index fluoride glass (ZBLAN) fiber with a 100/110-μm core/cladding diameter reached a length of approximately 12–15 mm from the input surface of the optical fiber, with the diameters ranging from 5 to 8 μm at input intensities more than 1.0×1012 W/cm2. The graded refractive-index profiles were fabricated to have a symmetric form from the center of a multimode fluoride fiber and a maximum value of the refractive-index change (Δn) was measured to be 1.3×10-2. The beam profile of the output beam transmitted through the modified multimode fibers showed that the photoinduced refractive-index modification produced a permanent structure of a single-mode waveguide.

A photographic colour film, which was exposed to heavy ions, reveals a coloured dye image of the ion tracks. Since the colour film consists of several layers and different colours appear on each layer, three-dimensional information on the tracks in the layers can be obtained by the colour image. Previously, we have reported the method for which the tracks in different colours represented differences of track depth and we also discussed the disadvantages of using commercial colour films. Here we present the procedure for a self-made photographic coating and the development formula which can overcome the disadvantages.

Neoxanthin, a precursor of the plant hormone abscisic acid, is an allenic xanthophyll recognized as the last product of carotenoid synthesis in green plants. A cDNA for neoxanthin synthase (NSY) was isolated from tomato using a molecular approach based on the mechanistic and structural similarities of NSY to two other closely related carotenogenic enzymes, lycopene cyclase (LCY) and capsanthin-capsorubin synthase (CCS). The identified tomato NSY cDNA (T.NSY) encodes a 56-kDa plastid-targeted protein that when expressed in Escherichia coli, catalyzes the conversion of violaxanthin to neoxanthin. In tobacco leaves that transiently express T.NSY, an increase in neoxanthin content with a concomitant decrease in violaxanthin is observed. NSY is structurally similar to LCY and CCS. However, in Cyanobacteria, the generally accepted progenitor of plastids, both CCS and NSY are absent while LCY is present. LCY catalyzes a simplified version of the reaction catalyzed by NSY and CCS suggesting that these two enzymes were remodeled from LCY during higher plant evolution to create new forms of oxidized carotenoids.

The dispersion of latent image specks (LISs) on reduction-sensitized octahedral grain (Oct) and cubic grain (Cub) emulsions that were exposed to light of various intensity levels or to a radiation was studied. The number and distribution of LISs on a grain were determined with arrested development or gold deposition techniques. The sensitized Oct emulsions were sensitive to extra-low-intensity (24 or 48 h) exposure. This exposure displayed a narrow distribution with a one-speck-per-grain pattern. This changed to a broad distribution for 1 s exposure, which obeyed the Poisson distribution law at the highest sensitization level. These suggested that there were P centres present acting as precursors of LISs and inducing dispersion. The distribution for high-intensity (10−4 s) exposure obeyed the Poisson law for sensitized Oct and Cub emulsions. This dispersion of LISs occurred even in absence of the effective electron traps, when the supply rate of photoelectrons was high.The distribution of LISs was...

A soluble fraction of coal tar pitch (CP) in tetrahydrofuran (THF) was reacted with p-benzoquinone (BQ) at 160 and 180°C and followed by carbonization and graphitization. The reaction and carbonization behavior were monitored in-situ by using differential scanning calorimeter, high-temperature 1H NMR and high-temperature ESR. The reactions of CP and BQ resulted in an increase in molecular weight with an increase in BQ concentration. Such molecular weight increases led to the formation of a less ordered structure due to the reduced mobility of the molecules. The relative order of the carbonized materials was determined by using polarized light microscope and X-ray diffraction. The molecular size of the precursor was recognized as an important factor in determining the morphology of carbon materials.

The neutron drip line up to fluorine has been investigated by the projectile fragmentation of a 94.1A MeV 40 Ar beam at the fragment separator RIPS at RIKEN. A new neutron-rich isotope, 31 F, has been observed for the first time while clear evidence for the particle instability of 24,25 N, 27,28 O and 30 F has been obtained. The sudden change in stability from oxygen to fluorine may demonstrate the onset of deformation for the neutron-rich fluorine isotopes.

The biosynthesis of leaf carotenoids in Nicotiana benthamiana was altered by forced re-routing of the pathway to the synthesis of capsanthin, a non-native chromoplast-specific xanthophyll, using an RNA viral vector containing capsanthin-capsorubin synthase (Ccs) cDNA. The cDNA encoding Ccs was placed under the transcriptional control of a tobamovirus subgenomic promoter. Leaves from transfected plants expressing Ccs developed an orange phenotype and accumulated high levels of capsanthin (up to 36% of total carotenoids). This phenomenon was associated with thylakoid membrane distortion and reduction of grana stacking. In contrast to the situation prevailing in chromoplasts, capsanthin was not esterified and its increased level was balanced by a concomitant decrease of the major leaf xanthophylls, suggesting an autoregulatory control of chloroplast carotenoid composition. Capsanthin was exclusively recruited into the trimeric and monomeric light-harvesting complexes of photosystem II (PSII) and shown to significantly contribute to the light-harvesting capacity. On a chlorophyll basis, the concentrations of PSI and PSII reaction centres were not modified. This demonstration that higher plant antenna complexes can accommodate non-native carotenoids provides compelling evidence for functional remodelling of photosynthetic membranes toward a better photoreactivity by rational design of the incorporated carotenoid structures.

A chimeric enzyme, engineered from two rice α-amylase isozymes, Amy1A and Amy3D, showed unique characteristics in soluble-starch and maltoheptaose hydrolysis. Effects of pH on soluble-starch hydrolysis and the thermostability of the chimeric enzyme were similar to those of the isozyme Amy3D. The previous study revealed that Amy1A shows high activity in soluble-starch hydrolysis and low activity in oligosaccharide degradation, while Amy3D shows low activity in soluble-starch hydrolysis and high activity in oligosaccharide degradation. The chimeric enzyme showed high activities in both soluble-starch hydrolysis and oligosaccharide degradation. These results suggest that protein modules of highly homologous enzymes are interchangeable, and that a novel enzyme with unique characteristics can be obtained by creating a chimeric enzyme.

The carotenoid biosynthetic pathway in higher plants was manipulated by using an RNA viral vector. A cDNA encoding phytoene synthase and a partial cDNA encoding phytoene desaturase (PDS) were placed under the transcriptional control of a tobamovirus subgenomic promoter. One to two weeks after inoculation, systemically infected Nicotiana benthamiana plants were analyzed for phytoene. Leaves from transfected plants expressing phytoene synthase developed a bright orange phenotype and accumulated high levels of phytoene. Cytoplasmic inhibition of plant gene expression by viral RNA was demonstrated with an antisense RNA transcript to a partial PDS cDNA derived from tomato. The leaves of the plants transfected with the antisense PDS sequence developed a white phenotype and also accumulated high levels of phytoene. A partial cDNA to the corresponding N. benthamiana PDS gene was isolated and found to share significant homology with the tomato antisense PDS transcript. This work demonstrates that an episomal RNA viral vector can be used to deliberately manipulate a major, eukaryotic biosynthetic pathway. In addition, our results indicate that an antisense transcript generated in the cytoplasm of a plant cell can turn off endogenous gene expression.

Mass/charge spectra of secondary ions produced under energetic (∼MeV/amu) Ar ion impact on gaseous and frozen H2O targets are measured using a magnet‐type mass spectrometer. The ion spectra are found to be quite different between these target phases. Multiply charged Oi+ ions with charge states i=2–6, as well as fragmented H+, O+, and OH+ ions, are clearly observed in the gas target, whereas the production of multiply charged ions is strongly suppressed in the frozen target. The most intense ion species is the parent H2O+ ion in the gas target; the H3O+ ion in the frozen target. The most outstanding feature in the frozen target is that the production of cluster ions of the type (H2O)nH+ (n=1–31), and their intensities, decreasing as the cluster size n increases, show anomalies between n=4 and n=5 and also around n=20, 21, and 22. Negatively charged cluster ions with formula (H2O)nO− and (H2O)nOH− are also efficiently produced in the frozen target.

Positive and negative cluster ions have been observed in nitrogen, carbon monoxide and oxygen targets frozen at 15 K under 1.5 MeV u −1 Ar 13+ projectile ion impact. For positive cluster ions obtained from frozen nitrogen targets, even-number cluster series ions N + 2 n for n > 2 predominate over odd-number cluster series N + 2 n +1 . This is in sharp contrast to the fact that odd-number cluster series N − 2 n +1 are dominant in negative nitrogen cluster ions. Anions of N − 2 , etc., which do not exist in the gas phase, have been observed. Various positive cluster ions from frozen carbon monoxide targets have been observed, although pure carbon clusters C − n are dominant in the negative cluster ions. Clusters ions from frozen oxygen targets are formed with clustering element O 3 ; the O + 3 n +2 series are the dominant positive cluster ions, whereas the O − 3 n +3 series are much stronger than either O − 3 n +2 as regards the negative cluster ions. In addition multiply charged atomic ions have been observed from all the frozen targets investigated; these can be explained qualitatively as being due to Coloumbic explosion of multiply charged molecular ions originally produced in primary energetic ion collisions.

Transgenic (TG) rats carrying the mouse Ren-2 gene (Ren-2d)27 are a newly established monogenetic model in hypertension research. To gain an insight into the mechanisms of this form of hypertension we determined the effects of a 13-day therapy with losartan (10 mg/kg) or lisinopril (20 mg/kg) on the blood pressure (BP) and plasma levels of angiotensin (ANG) peptides of mature female TG hypertensive and Sprague-Dawley (SD) rats. The contribution of endothelium-derived nitric oxide (NO) to the maintenance of their hypertension and the response to therapy was evaluated by systemic injection of either NG-monomethyl-L-arginine (L-NMMA) or endothelin-1. Hypertension in TG rats was associated with decreased plasma ANG I, no differences in plasma ANG II, and plasma ANG-(1-7) near the detectable level. Lisinopril lowered BP more than losartan in both TG hypertensive and normotensive controls. In both strains, the chronic fall in BP produced by lisinopril was accompanied by significant increases in plasma ANG I and ANG-(1-7), while losartan augmented plasma ANG I and ANG II in both strains and plasma ANG-(1-7) in TG rats. Inhibition of NO synthase reversed the fall in BP produced by either lisinopril or losartan in SD controls. In contrast, administration of L-NMMA to TG rats given the same therapy did not. The transient endothelium-mediated relaxing phase of the depressor response to systemic injections of endothelin-1 was attenuated by losartan and lisinopril in TG rats. These studies indicate that hypertension in female TG rats is mediated by the RAS.(ABSTRACT TRUNCATED AT 250 WORDS)

Secondary ions produced from condensed rare gas targets are observed under MeV amu , highly charged, heavy ion impact. The intensities of the observed cluster ions decrease smoothly as the cluster sizes become large but show some discontinuities at particular sizes of cluster ions. This seems to be closely related to the stabilities of cluster ion structures. It is also noted that very few doubly charged or practically no triply/higher charged ions have been observed, in sharp contrast to that of some condensed molecular targets.

Signet ring cell lymphoma (SRCL) is a relatively new and infrequently described entity, characterized by an intracytoplasmic mass displacing the nucleus at the periphery. We present here a case of a Japanese female aged 73 with a retroperitoneal mass diagnosed as SRCL at autopsy. The neoplastic lymphoid cells showing signet ring appearance, due to the displacement of the nucleus to one side by intracytoplasmic eosinophilic inclusions, were immunoreactive for LCA, L26 and lambda light chains but PAS-negative. A small number of tumor cell nuclei demonstrated proliferating cell nuclear antigen-positive, but signet ring cells were negative. Ultrastructural study disclosed that fibrillary, lamellar or homogenous materials within rough endoplasmic reticulum of the tumor cells were selectively labeled by gold particles to anti-lambda antibody. A periodicity of 20-25 nm was observed in the fibrillary inclusions arranged haphazardly. The morphologic appearances of the case and the differential diagnosis are preceded by a review of the literature.

A recombinant Saccharomyces cerevisiae, expressing and secreting rice alpha-amylase, converts starch to ethanol. The rice alpha-amylase gene (OS103) was placed under the transcriptional control of the promoter from a newly described Pichia pastoris alcohol oxidase genomic clone. The nucleotide sequences of ZZA1 and other methanol-regulated promoters were analyzed. A highly conserved sequence (TTG-N3-GCTTCCAA-N5-TGGT) was found in the 5' flanking regions of alcohol oxidase, methanol oxidase, and dihydroxyacetone synthase genes in Pichia pastoris, Hansenula polymorpha, and Candida boidinii S2. The yeast strain containing the ZZA1-OS103 fusion secreted biologically active enzyme into the culture media while fermenting soluble starch.

The reactions of 1-seleno-2-silylethenes 1 with highly electrophilic tricarbonyl-substitued olefins in the presence of Lewis acids have been investigated. The reaction of 1-(phenylseleno)-2-(trimethylsilyl)ethene (1a) with tris(alkoxycarbonyl) olefins 2 or 1,1-bis(alkoxycarbonyl)-2-acyl olefins 3 in the presence of ZnBr(2) at -30 degrees C gave cis-substituted cyclopropanes exclusively. The origin of the cis stereochemistry is ascribed to the synclinal addition path of the ZnBr(2)-coordinated electrophilic olefin to 1. Application of the highly functionalized selenium- and silicon-substituted cyclopropane products to the preparation of a useful synthetic intermediate 20 for the pyrethroid class of insecticides is also demonstrated.

Secondary ions have been measured due to collisions of 1.25 MeV/amu Arq+ (q = 12 or 14) projectile ions with C2H2 molecular targets frozen on a thin foil which was cooled to liquid nitrogen temperature. In the present experiments, positively charged cluster ions such as [CHm(C2)n]+ and[C2Hm(C2)n]+ (m = 0, 1, 2 or 3) and negatively charged cluster ions [CHm(C2)n]− and [C2Hm(C2)n]− (m = 0 or 1) have been observed. The charge/mass spectrum of the atomic and molecular ions frozen C2H2 targets was also found to be quite different from that in gaseous C2H2 targets.

A variety of cluster ions, positive or negative, as well as multiply charged atomic ions have been observed from the frozen CO2 targets under (MeV/amu) energetic, highly charged projectile ion impact. Their spectra are found to be quite different from those produced in the cooled expanding CO2 gas targets.

Collisions between 1.05 MeV/amu Arq+ (q = 14, 10, 8 and 4) ions and CH4 molecules have been investigated using final charge-selected projectile-recoil ion time-of-flight technique. It is found that, in the overall ionization of target CH4 molecules, pure ionization processes without any change of the projectile charge is by far dominant over any other processes involving electron capture or loss of projectiles. Electron loss or capture processes of projectiles, though weak relative to pure ionization, are found to result in enhancement of the production of multiply charged atomic carbon ions. Another feature, probably not observed earlier, is the fact that in some electron loss and capture processes multiply charged carbon ions become more dominant than any other molecular ions, suggesting that such violent collisions result in nearly complete dissociation of the molecular ions.

We examined the hypothesis that the positive inotropic effect of angiotensin I (Ang I) may be retained in the presence of angiotensin converting enzyme inhibitors so that it may have a direct beneficial effect on the heart. Accordingly, isolated perfused hearts (Langendorff preparation) of 300-day-old cardiomyopathic hamsters (a model of spontaneous cardiomyopathy) and age-matched normal hamsters (controls) were infused with Ang I in the presence of captopril; propranolol was added to the perfusing medium to block catecholamine-mediated effects of angiotensins on the heart. Left ventricular developed pressure and the rate of increase in left ventricular developed pressure increased significantly (p less than 0.001) in both the cardiomyopathic and the normal hamster heart despite concomitant reduction in myocardial flow rate favoring a direct inotropic effect of Ang I in both normal and myopathic hearts; these changes were significantly higher by almost threefold in the cardiomyopathic than in the normal hamsters (p less than 0.01) and were blocked by the angiotensin II (Ang II) antagonist [Sar1,Thr8]Ang II. Comparing dose-left ventricular contractility response curves for Ang I and Ang II, ED50 for responses was identical in both normal and myopathic hearts, whereas peak responses to Ang II were double those to Ang I in normal hearts but were almost identical in the myopathic hearts. Binding of [125I]Ang II in six cardiomyopathic and four normal hamster hearts was of high affinity, but there was no evidence for Ang I-saturable high-affinity binding sites.(ABSTRACT TRUNCATED AT 250 WORDS)

A particle identification technique has been developed combining the use of a position-sensitive silicon detector with a simple magnetic system. Measurements of time of flight, energy loss, total energy, and magnetic rigidity provided the determination of the atomic number, the charge state, and the mass of produced fragments. The resultant resolutions were ΔA = 0.34 (FWHM) for mass number A = 40 and ΔZ = 0.24 (FWHM) for atomic number Z = 20.

The charge distributions and production cross sections of recoil ions accompanied by projectile electron loss and capture have been compared in 1.05-MeV/amu Ne{sup {ital q}+} ({ital q}=2, 4, 6, 8, and 10) +Ne collisions. While singly charged recoil ions are dominant in pure ionization processes, the production of highly charged recoil ions is strongly enhanced in collisions involving simultaneous charge change (by both electron loss and capture) of projectiles, and the charge distributions of recoil ions are found to be similar for both projectile loss and capture processes. These results have been analyzed with an independent-electron model and indicate that the dominant contribution to the production of higher-charge recoil ions comes from {ital L}-shell ionization, with some contribution from {ital K}-shell ionization of targets, accompanied by violent multiple ionization of projectiles.

We report the high level expression and secretion of rice α-amylase isozyme by Saccharomyces cerevisiae . Transcription of this gene was under control of the yeast enolase promoter. The synthesized protein had an approximate molecular size of 45 kDa and a pI of approx 4.7 to 5.0. The rice α-amylase signal peptide was recognized and efficiently processed by yeast and the active, glycosylated enzyme was secreted into the culture media. This enzyme was purified to homogeneity by affinity chromotography and its enzymatic properties were characterized. The K m and V max were found to be similar to those of α-amylase from other organisms. The high level of secretion observed in these studies may be due to the unique features of the rice signal peptide and/or to the glycosylation of the recombinant enzyme.

Nickel oxide films have been fabricated by various physical and chemical vapour deposition (CVD) techniques such as reactive sputtering [1] and plasma-enhanced chemical vapour deposition [2] because their chemical stability as well as their optical and electrical properties are excellent. If the fabrication technology could lead to growth on an atomic scale, it would be rauch more interesting also for applications to soft X-ray multilayers and neutron optics because compound multilayer structures consisting of NiXx (X = C, N, dry air) layers have been the focus of recent attention [3]. In recent years, atomic layer deposition of A1203 [4-7], TiO2 [8, 9] and multilayers based on A1203/TiO2 [10] by sequential surface chemical reactions has been reported. This deposition technique could be used to sequentially dose a surface with appropriate chemical precursors to promote surface chemical reactions that are inherently self-limiting. The selflimiting nature of the surface reactions enables precise control of the thickness of the deposited layers on an atomic scale and gives rise to homogeneous films on large areas. In this work, bis-methylcyclopentadienyl nickel (Ni(CH3CsH4)2) and hydrogen peroxide (H202) were used for controlled growth of amorphous nickel oxide films by sequential surface chemical reactions, because amorphous structures are suitable for applications to soft X-ray multilayers due to their smooth surface and interface. The experimental setup comprised a stainless steel vacuum chamber with computer-controlled leak and gare valves, a capacitor manometer and a substrate holder connected to a heater. The substrate was cut from a (100)-orientated Si wafer. As vapour sources, high purity bis-methylcyclopentadienyl nickel (Ni(CH3C»H4)2; Trichemical Laboratory Inc.) and H 2 0 2 w e r e used. As shown in Fig. 1, the vapour pressure of Ni(CH3CsH4)2 is high among those of nickel compounds [11], which makes it rather easy to u s e . H 2 0 2 w a s prepared by vacuum distilling

In this paper, we report that we could demonstrate experimentally high reflectance (71.8/spl deg/) over 30% for soft X-ray multilayer mirrors, at 2.734 nm near the titanium L/sub 2,3/ absorption edge located at 2.729 nm, by novel metal oxide multilayers of titanium oxide and aluminum oxide fabricated by the atomic layer deposition method.

Recently so called "atom lithography", which makes the most use of atom deposition techniques with an optical mask, has been studied. This technique has been enable to fabricate nanometer-size structure. To apply this technique to silicon, it is necessary to develop the laser system that emits deep ultraviolet light resonant to it.

Tobamoviral vectors have been developed for the heterologous expression of glycoproteins in plants. The rice alpha-amylase gene (OS103) was placed under the transcriptional control of a tobamovirus subgenomic promoter in a RNA viral vector. One to two weeks after inoculation, transfected Nicotiana benthamiana plants accumulated glycosylated alpha-amylase to levels of at least 5% total soluble protein. The 46kDa recombinant enzyme was purified, and its structural and biological properties were analyzed. Post-translational modifications of the secreted protein were compared to rice alpha-amylase expressed in amylolytic strains of Pichia pastoris and Saccharomyces cerevisiae. Endo-H analysis revealed that the alpha-amylase was moderately glycosylated in transfected plants and hyperglycosylated in yeast.

The rnfABCDE genes in Rhodobacter capsulatus are essential for diazotrophic growth under illuminated conditions. They locate near fdxN gene whose product is a major electron donor to nitrogenase. Since disruption of rnf genes conferred metronidazole resistance under pseudo-diazotrophic conditions and two of the rnf products, RnfB and RnfC, are supposed to hold iron-sulfur clusters, the genes are expected to encode some ferredoxin reductase. Because most of rnf products are highly hydrophobic it is hypothesized that rnf products constitute a membrane protein complex. In this study, we have 1) experimentally investigated their presence at chromatophore membranes, 2) made a prediction of enzymatic function and 3) collected data that the rnf products also serve for nitrogen fixation in darkness and that their homologs present in non-diazotrophs.

The neutron drip line determination up to fluorine has been performed by projectile fragmentation of a 94.1AMeV 40Ar beam at the fragment separator RIPS at RIKEN. A new neutron-rich isotope 31F has been observed for the first time while clear evidence for the particle instability of 25N and 28O has been obtained. The sudden change of stability from oxygen to fluorine may demonstrate the onset of a deformation for the neutron-rich fluorine isotopes.

The reactions of 1-seleno-2-silylethenes 1 with highly electrophilic tricarbonyl-substitued olefins in the presence of Lewis acids have been investigated. The reaction of 1-(phenylseleno)-2-(trimethylsilyl)ethene (1a) with tris(alkoxycarbonyl) olefins 2 or 1,1-bis(alkoxycarbonyl)-2-acyl olefins 3 in the presence of ZnBr(2) at -30 degrees C gave cis-substituted cyclopropanes exclusively. The origin of the cis stereochemistry is ascribed to the synclinal addition path of the ZnBr(2)-coordinated electrophilic olefin to 1. Application of the highly functionalized selenium- and silicon-substituted cyclopropane products to the preparation of a useful synthetic intermediate 20 for the pyrethroid class of insecticides is also demonstrated.

Copper-containing monoamine oxidase (EC 1.4.3.6) from Escherichia coli is a periplasmic enzyme containing topa quinone in addition to divalent copper as a cofactor. The amino acid sequence of E. coli monoamine oxidase was compared to several cloned amine oxidase genes and five well-conserved histidine residues were found. Site-directed mutagenesis studies were performed to determine which histidine residue serves as the binding Ligand to the copper. Enzyme activity, absorption spectrum, and atomic absorption spectrophotometry of the mutant enzymes indicated that histidines 470, 554, and 556 are the copper binding ligands. The absorption spectra of phenylhydrazine derivatives suggested that copper is necessary for topa quinone formation.

Iron constituting the inner core of the Earth is probably of e‐phase with hexagonal closest packing structure stable only above 10 GPa. The elastic properties of e‐iron can be studied by using analogue materials, solid solutions of iron with ruthenium, which take hcp at relevant condition. Single crystalline ruthenium sample was grown by means of floating zone method and its elastic parameters and internal frictions were determined with an FT (Fourier Transform) ultrasonic spectroscopy introduced successfully to RST (Resonant Sphere Technique). The potentiality of the new method is discussed in relation to the study of physical properties of iron in high pressure phase.

The atomic layer epitaxy of wurtzite thin films on sapphire (001) substrates was studied in the controlled growth of zinc oxide films by sequential surface chemical reactions using a vapor combination of diethylzinc (Zn(CH2CH3)2) and water (H2O). The optical constant and thickness of these wurtzite films were investigated in terms of the Zn(CH2CH3)2 and H2O vapor pressures using a variable-angle spectroscopic ellipsometer. As a result, the self-limiting nature of the atomic layer epitaxy of wurtzite thin films was demonstrated successfully under various conditions of the dosing reactant vapors, whereby the growth rate was almost constant at approximately 0.26 nm/cycle (2.6 nm/min) and the index of refraction was also constant at 1.94.

Various secondary ions have been produced under 1.5-MeV/amu Ar 13+ -ion impact on a condensed CO target. Multiply charged C i+ and O i+ ions including H- and He-like ions have been observed to be unexpectedly large compared with condensed rare-gas targets and understood to be due to large initial kinetic energies, which are gained through Coulomb explosion of multiply charged molecular ions produced inside condensed targets during energetic collisions. The prominent positive cluster ions are [CO(CO) n ] + as expected, whereas the negative cluster ions are [C n ]